metasploit-gs/How-to-Send-an-HTTP-Request-Using-HTTPClient.md

This is an example of how to write a module that uses the [HttpClient](https://rapid7.github.io/metasploit-framework/api/Msf/Exploit/Remote/HttpClient.html) mixin to send a basic HTTP request.

### There are mainly two common methods you will see:

* **[send_request_raw](https://rapid7.github.io/metasploit-framework/api/Msf/Exploit/Remote/HttpClient.html#send_request_raw-instance_method)** - You use this to send a raw HTTP request. Usually, you will want this method if you need something that violates the specification; in most other cases, you should prefer `send_request_cgi`.  If you wish to learn about how this method works, look at the documentation for [`Rex::Proto::Http::Client#request_raw`](https://rapid7.github.io/metasploit-framework/api/Rex/Proto/Http/Client.html#request_raw-instance_method).
 
Here's a basic example of how to use `send_request_raw`:

```ruby
	send_request_raw({'uri'=>'/index.php'})
```

* **[send_request_cgi](https://rapid7.github.io/metasploit-framework/api/Msf/Exploit/Remote/HttpClient.html#send_request_cgi-instance_method)** - You use this to send a more CGI-compatible HTTP request. If your request contains a query string (or POST data), then you should use this.  If you wish to learn about how this method works, check out [`Rex::Proto::Http::Client#request_cgi`](https://rapid7.github.io/metasploit-framework/api/Rex/Proto/Http/Client.html#request_cgi-instance_method).

Both methods can automatically do the HTTP authentication if the user sets the "USERNAME" and "PASSWORD" advanced options.

Here's a very basic example for `send_request_cgi`:

```ruby
	send_request_cgi({
		'method'   => 'GET',
		'uri'      => '/hello_world.php',
		'vars_get' => {
			'param_1' => 'abc',
			'param_2' => '123'
		}
	})
```

**Please note**: `send_request_raw` and `send_request_cgi` will return a `nil` if there's a timeout, so please make sure to account for that condition when you handle the return value.

### URI Parsing

Before you send a HTTP request, you will most likely have to do some URI parsing.  This is a tricky task, because sometimes when you join paths, you may accidentally get double slashes, like this: "/test//index.php".  Or for some reason you have a missing slash.  These are really commonly made mistakes.  So here's how you can handle it safely:

**1** - Register your default URI datastore option as 'TARGETURI':

Example:

```ruby
	register_options(
		[
			OptString.new('TARGETURI', [true, 'The base path to XXX application', '/xxx_v1/'])
		], self.class)
```

**2** - Load your TARGETURI with [`target_uri`](https://rapid7.github.io/metasploit-framework/api/Msf/Exploit/Remote/HttpClient.html#target_uri-instance_method), that way the URI input validation will kick in, and then you get a real `URI` object:

In this example, we'll just load the path:

```ruby
	uri = target_uri.path
```

**3** - When you want to join another URI, always use [`normalize_uri`](https://rapid7.github.io/metasploit-framework/api/Msf/Exploit/Remote/HttpClient.html#normalize_uri-instance_method):

Example:

```ruby
	# Returns: "/xxx_v1/admin/upload.php"
	uri = normalize_uri(uri, 'admin', 'upload.php')
```

**4** - When you're done normalizing the URI, you're ready to use `send_request_cgi` or `send_request_raw`

Please note: The `normalize_uri` method will always follow these rules:

1. The URI should always begin with a slash.
2. You will have to decide if you need the trailing slash or not.
3. There should be no double slashes.

### Full Example

```ruby

	require 'msf/core'

	class Metasploit3 < Msf::Auxiliary

		include Msf::Exploit::Remote::HttpClient

		def initialize(info = {})
			super(update_info(info,
				'Name'           => 'HttpClient Example',
				'Description'    => %q{
					Do a send_request_cgi()
				},
				'Author'         => [ 'sinn3r' ],
				'License'        => MSF_LICENSE
			))

			register_options(
				[
					OptString.new('TARGETURI', [true, 'The base path', '/'])
				], self.class)
		end


		def run
			uri = target_uri.path

			res = send_request_cgi({
				'method'   => 'GET',
				'uri'      => normalize_uri(uri, 'admin', 'index.phpp'),
				'vars_get' => {
					'p1' => "This is param 1",
					'p2' => "This is param 2"
				}
			})

			if res && res.code == 200
				print_good("I got a 200, awesome")
			else
				print_error("No 200, feeling blue")
			end
		end
	end
```

### Common question(s):

**1 - Can I use ```vars_get``` and ```vars_post``` together?**

Yes. When you supply a hash to ```vars_get```, basically it means "put all this data in the query string". When you supply a hash to ```vars_post```, it means "put all this data in the body." All of them will be in the same request. You do need to make sure you're using ```send_request_cgi```, of course.

**2 - I can't use ```vars_get``` or ```vars_post``` due to some weird reason, what to do?**

Do mention about this problem in the code (as a comment). If you can't use ```vars_post```, you can try the ```data``` key instead, which will send your post data raw. Normally, the most common solution to get around ```vars_get``` is to leave your stuff in the ```uri``` key. msftidy will flag this, but only as an "Info" and not a warning, which means you should still pass msftidy anyway. If this is a common problem, we can always change msftidy.

## References

https://github.com/rapid7/metasploit-framework/wiki/How-to-send-an-HTTP-request-using-Rex%3A%3AProto%3A%3AHttp%3A%3AClient